Major virtual assistants found to respond to silent ultrasonic voice commands

Virtual assistants like Google Assistant and Amazon Alexa can be abused, but you’d know if someone was telling your virtual assistant to do something like order products or open your house door.

Unfortunately, researchers at Zheijiang University in China found that these assistants can understand commands converted to ultrasonic frequencies. These commands are over 20,000 Hz and cannot be heard by the human ear, but a microphone can pick up these commands and the assistants can understand and respond to them. This means that, if your phone is listening for its command, someone can potentially force your phone to do things without you knowing.

Sixteen devices were tested and all responded properly, including phones, MacBooks, and even an Audi Q3. On the Audi, the navigation destination was changed via ultrasonic commands. I’m surprised to hear this works, since my car doesn’t even understand my voice at normal frequencies.

Fortunately, this isn’t as big a danger as it sounds. Your assistant would obviously respond via the speaker and popping up on the screen, so you’d likely notice if something was going on. The range on this tech is also around five or six feet so far. Your phone would also have to be unlocked, so keep your phone secure!